#VU81661 Out-of-bounds read in Linux kernel - CVE-2023-3865

Vulnerability identifier: #VU81661

Vulnerability risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-3865

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a remote user to gain access to potentially sensitive information or perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary condition within the ksmbd_smb2_check_message() function in fs/smb/server/smb2misc.c when parsing smb2_hdr structure. A remote user can send specially crafted packets to ksmbd, trigger an out-of-bounds read error and read contents of memory or perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://www.zerodayinitiative.com/advisories/ZDI-23-980/
https://lore.kernel.org/all/20230626180806.056931954@linuxfoundation.org/
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5fe7f7b78290638806211046a99f031ff26164e1

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.